Patients with sarcomas are studied for evidence of serum reactivity against tumor-specific determinants expressed on cultured syngeneic and allogeneic tumor cells using techniques of immunofluorescent staining. Roles of tissue-specific xenogeneic antibodies are investigated for possible approaches to developing methods of immunotherapy in a carcinogen-induced pancreatic carcinoma in hamsters. Intraoperative radiotherapy in dogs is evaluated for dose-response and normal tissue tolerance to electron-beam irradiation as part of an attempt to adapt operative radiotherapy to the treatment of human abdominal malignancies.